Related Clues:

• Musical composition
• See 54-Across
• Foursome
• See 58-Across
• Musical work
• Chamber group
• The Beatles, e.g.
• Barbershop group?
• Many a pop group
• Kiss, e.g.
• Group of four
• It's 44, by the sound of it.
• That's got four 31 acrosses
• A set of four for the volume, and in Latin
• Group of four musicians